Hi,
I have a volume upper filter driver. In cases where the volume has a file
system (NTFS/Fat), how big a single read or write request
(IRP_MJ_READ/WRITE) can be issued by the File System Driver. Even a
theoretical input on this will be OK.
Thanks
Normally it will be 64KB (max mm I/O size,) but it is possible for an
application performing non-cached I/O to write up to the maximum size
reported back by the underlying disk device (see
IOCTL_STORAGE_QUERY_PROPERTY for example, documented in the IFS Kit
docs.)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources Inc.
http://www.osr.com http:</http:>
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 2:09 PM
To: ntfsd redirect
Subject: [ntfsd] Read and write size
Hi,
I have a volume upper filter driver. In cases where the volume has a
file system (NTFS/Fat), how big a single read or write request
(IRP_MJ_READ/WRITE) can be issued by the File System Driver. Even a
theoretical input on this will be OK.
Thanks
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Thanks Tony! STORAGE_ADAPTER_DESCRIPTOR has a field called Maximum Transfer
Length. Are you referring about this?( Isn’t this talk about HBA
capabilities) I thought we should be looking at STORAGE_DEVICE_DESCRIPTOR.
And this does not have anything related to above. (This contains SCSI-2
Inquiry Command output for the device).
From: Tony Mason [mailto:xxxxx@osr.com]
Sent: Wednesday, May 12, 2004 11:47 AM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Read and write size
Normally it will be 64KB (max mm I/O size,) but it is possible for an
application performing non-cached I/O to write up to the maximum size
reported back by the underlying disk device (see
IOCTL_STORAGE_QUERY_PROPERTY for example, documented in the IFS Kit docs.)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources Inc.
http://www.osr.com http:</http:>
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com]
On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 2:09 PM
To: ntfsd redirect
Subject: [ntfsd] Read and write size
Hi,
I have a volume upper filter driver. In cases where the volume has a file
system (NTFS/Fat), how big a single read or write request
(IRP_MJ_READ/WRITE) can be issued by the File System Driver. Even a
theoretical input on this will be OK.
Thanks
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@legato.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Generally I would expect the adapter to restrict the maximum size of the
transfer, not the underlying disk device, but I suppose it could be
either one. You might ask in the NTDEV group, since most of the lower
level storage people hang out over there (away from people like us who
eschew hardware!)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com http:</http:>
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 3:03 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Read and write size
Thanks Tony! STORAGE_ADAPTER_DESCRIPTOR has a field called Maximum
Transfer Length. Are you referring about this?( Isn’t this talk about
HBA capabilities) I thought we should be looking at
STORAGE_DEVICE_DESCRIPTOR. And this does not have anything related to
above. (This contains SCSI-2 Inquiry Command output for the device).
From: Tony Mason [mailto:xxxxx@osr.com]
Sent: Wednesday, May 12, 2004 11:47 AM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Read and write size
Normally it will be 64KB (max mm I/O size,) but it is possible for an
application performing non-cached I/O to write up to the maximum size
reported back by the underlying disk device (see
IOCTL_STORAGE_QUERY_PROPERTY for example, documented in the IFS Kit
docs.)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources Inc.
http://www.osr.com http:</http:>
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 2:09 PM
To: ntfsd redirect
Subject: [ntfsd] Read and write size
Hi,
I have a volume upper filter driver. In cases where the volume has a
file system (NTFS/Fat), how big a single read or write request
(IRP_MJ_READ/WRITE) can be issued by the File System Driver. Even a
theoretical input on this will be OK.
Thanks
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@legato.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Adapter.
The disk class driver just splits the MDLs to satisfy the adapter’s limit, and the splitting code is rewritten from scratch in XP to be more parallel.
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
----- Original Message -----
From: Tony Mason
To: Windows File Systems Devs Interest List
Sent: Wednesday, May 12, 2004 11:10 PM
Subject: RE: [ntfsd] Read and write size
Generally I would expect the adapter to restrict the maximum size of the transfer, not the underlying disk device, but I suppose it could be either one. You might ask in the NTDEV group, since most of the lower level storage people hang out over there (away from people like us who eschew hardware!)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 3:03 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Read and write size
Thanks Tony! STORAGE_ADAPTER_DESCRIPTOR has a field called Maximum Transfer Length. Are you referring about this?( Isn’t this talk about HBA capabilities) I thought we should be looking at STORAGE_DEVICE_DESCRIPTOR. And this does not have anything related to above. (This contains SCSI-2 Inquiry Command output for the device).
From: Tony Mason [mailto:xxxxx@osr.com]
Sent: Wednesday, May 12, 2004 11:47 AM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Read and write size
Normally it will be 64KB (max mm I/O size,) but it is possible for an application performing non-cached I/O to write up to the maximum size reported back by the underlying disk device (see IOCTL_STORAGE_QUERY_PROPERTY for example, documented in the IFS Kit docs.)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources Inc.
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 2:09 PM
To: ntfsd redirect
Subject: [ntfsd] Read and write size
Hi,
I have a volume upper filter driver. In cases where the volume has a file system (NTFS/Fat), how big a single read or write request (IRP_MJ_READ/WRITE) can be issued by the File System Driver. Even a theoretical input on this will be OK.
Thanks
Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@legato.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Any.
If the user app will open the file noncached, and do a huge ReadFile, and the file is not fragmented - then the ReadFile’s size will be propagated down to the disk stack.
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
----- Original Message -----
From: Pashupati Kumar
To: Windows File Systems Devs Interest List
Sent: Wednesday, May 12, 2004 10:08 PM
Subject: [ntfsd] Read and write size
Hi,
I have a volume upper filter driver. In cases where the volume has a file system (NTFS/Fat), how big a single read or write request (IRP_MJ_READ/WRITE) can be issued by the File System Driver. Even a theoretical input on this will be OK.
Thanks
Questions? First check the IFS FAQ at https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
Thanks to all! I got the answer I was looking for.
From: Maxim S. Shatskih [mailto:xxxxx@storagecraft.com]
Sent: Wednesday, May 12, 2004 12:17 PM
To: Windows File Systems Devs Interest List
Subject: Re: [ntfsd] Read and write size
Adapter.
The disk class driver just splits the MDLs to satisfy the adapter’s
limit, and the splitting code is rewritten from scratch in XP to be more
parallel.
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com mailto:xxxxx
http://www.storagecraft.com http:
----- Original Message -----
From: Tony Mason mailto:xxxxx
To: Windows File mailto:xxxxx Systems Devs Interest List
Sent: Wednesday, May 12, 2004 11:10 PM
Subject: RE: [ntfsd] Read and write size
Generally I would expect the adapter to restrict the maximum size of the
transfer, not the underlying disk device, but I suppose it could be either
one. You might ask in the NTDEV group, since most of the lower level
storage people hang out over there (away from people like us who eschew
hardware!)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com http:</http:>
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com]
On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 3:03 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Read and write size
Thanks Tony! STORAGE_ADAPTER_DESCRIPTOR has a field called Maximum Transfer
Length. Are you referring about this?( Isn’t this talk about HBA
capabilities) I thought we should be looking at STORAGE_DEVICE_DESCRIPTOR.
And this does not have anything related to above. (This contains SCSI-2
Inquiry Command output for the device).
From: Tony Mason [mailto:xxxxx@osr.com]
Sent: Wednesday, May 12, 2004 11:47 AM
To: Windows File Systems Devs Interest List
Subject: RE: [ntfsd] Read and write size
Normally it will be 64KB (max mm I/O size,) but it is possible for an
application performing non-cached I/O to write up to the maximum size
reported back by the underlying disk device (see
IOCTL_STORAGE_QUERY_PROPERTY for example, documented in the IFS Kit docs.)
Regards,
Tony
Tony Mason
Consulting Partner
OSR Open Systems Resources Inc.
http://www.osr.com http:</http:>
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com]
On Behalf Of Pashupati Kumar
Sent: Wednesday, May 12, 2004 2:09 PM
To: ntfsd redirect
Subject: [ntfsd] Read and write size
Hi,
I have a volume upper filter driver. In cases where the volume has a file
system (NTFS/Fat), how big a single read or write request
(IRP_MJ_READ/WRITE) can be issued by the File System Driver. Even a
theoretical input on this will be OK.
Thanks
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@legato.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@osr.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
—
Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
You are currently subscribed to ntfsd as: xxxxx@legato.com
To unsubscribe send a blank email to xxxxx@lists.osr.com</mailto:xxxxx></mailto:xxxxx></http:></mailto:xxxxx>